Test Methods: ASTM D 2794, D 5420, D 3029, D 4226 and G14
Gardner impact tester model IG-1120 has gained wide acceptance as a means of testing the impact resistance of many types of coatings from paints and vanishes to tough plated, plastic or laminated coatings. It is also used to establish quality standards for resistance to impact surface damage and penetration of many construction materials such as plastics, resins, fibreglass, sheet metals, plywood, etc. Two models, one calibrated in English units and one in Metric, are structurally identical except for the weights that are supplied with each model. Tolerance of weight is +/- 2 oz. The specimen is placed over a hole of 0.640 in. (1.63 cm) diameter in a die mounted in the anvil. The round nosed punch, 0.625 in (1.59cm) diameter, is placed upon the specimen. The weight is raised to the desired height in the 40 in. or 100cm graduated guide tube and dropped. Damage to the sample may be determined visually or with low power magnification or by using a Holiday detector. Weights of 2 and 4 pounds offer impact forces of 80 and 160 inch-lbs. respectively, while the 1 kg and 2 kg weights can exert forces of 100 kg-cm and 200 kg-cm…..